Rails gem "friendly_id": How to get a live preview of the slug, before its object is created

Using the Rails gem "friendly_id", is it possible to get a "live preview" of the slug to be created? Before the object is saved, that is (and to be returned while typing using an ajax request)?

If so, how?

FriendyId author here.

FriendlyId internally uses the private set_slug to do this. This method is invoked via a before_validation callback. If for some reason you do not wish to call valid?, you can invoke the set_slug method via send, or define a method in your model which invokes it:

instance = ModelClass.new
instance.send(:set_slug)

# or
class ModelClass < ActiveRecord::Base
  friendly_id :name, use: :slugged

  def generate_slug_preview
    set_slug
  end
end 

However, note that bypassing or ignoring validations is often a bad idea. For example, if your model included a validation on the name field, and then you used that field as the basis of the slug, then you are previewing a slug that will never actually be generated.